A relatively large, yellowish brown freshwater unionid commonly found throughout the midwestern United States. This bivalve can be identified by its heavy shell, shallow depth of beak cavity, large pseudocardinal teeth and oblong shape. Young show distinct green rays radiating from the beak. While commonly defined as mussels, many leading malacologists identify muckets as unionids seperate from mussels. A distinguishing difference is that they lack the byssal threads used by many bivalves, including mussels, to hold themselves to rocks and other fixed structures. Several other species, such as the Pink Mucket, utilize the common name but are of a different subfamily.